Direct access storage devices (DASD) have become part of every day life, and as such, expectations and demands continually increase for greater speed for manipulating data and for holding larger amounts of data. To meet these demands for increased performance, the mechanical assembly in a DASD device, specifically the Hard Disk Assembly (HDA) has undergone many changes.
Vibration can limit the performance of an HDD. Vibrations that enter the HDD from external sources are controllable by various methods and systems well known in the art. These methods can range from vibration absorbent materials to extraneous systems such as shock absorbers and active vibration control systems with feedback loops.
Internal vibrations that are generated by components within the HDD can present challenges to HDD designers. Sources of internal vibrations are typically those components that need to move to perform their desired function, such as the actuator assembly and motor-hub assembly. The performance requirements of the HDD to access and store data determine the speed and cyclic frequency at which the actuator assembly moves and the speed at which the motor-hub assembly rotates. When unwanted vibrations occur due to the speed of the actuator assembly and motor-hub assembly, their mitigation can be very challenging.